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Biomedical subjects

J Olsen

Publications and source records attributed to J Olsen.

At least 199 records · Page 11Linked to original sources
PubMed1998

Outcome of pre-hospital antibiotic treatment of meningococcal disease.

OBJECTIVE: To assess the effect of pre-hospital antibiotic treatment given by general practitioners to patients with meningococcal disease. DESIGN: A 16-year population-based historical follow-up study based on referral letters and hospital records in the County of North Jutland, Denmark. SUBJECTS: 320 patients with meningococcal disease, of whom 302 were examined by a general practitioner before admission to hospital. MAIN OUTCOME MEASURES: Death. RESULTS: 44 patients (14.6%) were given antibiotic treatment by the referring general practitioner. Nine of these (20.5%) died, compared with 16 (6.2%) patients who did not receive pre-hospital antibiotic treatment. The presence of skin bleeding, petechiae, and impaired consciousness were strongly associated with case fatality. Even after adjustment for these variables the odds ratio (OR) for death in patients treated with antibiotics was high (OR = 3.2; 95% CI, 0.9-10.6). In the 15 patients with skin bleeding (ecchymoses, suggillations) the case fatality rate was 100% in patients treated with antibiotics, and 50% in patients who did not receive antibiotics before hospitalization. If skin bleeding was replaced in the models by the presence of disseminated intravascular coagulation on admission, the OR for death in patients with pre-hospital antibiotic treatment was 35.9 (95% CI, 2.9-441.8) in the presence of disseminated intravascular coagulation and 1.9 (95% CI, 0.2-19.5) in its absence. CONCLUSIONS: Pre-hospital treatment is mainly given to the most severe cases with expected high case fatality, and this confounding by indication was probably not fully adjusted for with the available data. The results contradict previous findings but provide reason to doubt the benefit of pre-hospital antibiotic treatment in patients with meningococcal disease.

Adolescent↗
PubMed1998

Risk of colorectal cancer in relatives of patients with inflammatory bowel disease (Denmark)

OBJECTIVES: It has been suggested that inflammatory bowel disease (IBD) and colon cancer are associated because they have genetic susceptibility in common, rather than IBD causing cancer. We examined the risk of colorectal cancer in first-degree relatives of patients with IBD in order to evaluate if they share the same genetic susceptibility. METHODS: We identified patients with IBD in the Danish Hospital Discharge Registry. A cohort of all first-degree relatives to these patients were linked to the Danish Cancer Registry. Colorectal cancers observed were compared with expected values based on age, gender, and calendar-specific incidence rates in the general population. RESULTS: Among 4,496 patients with IBD, a total of 19,645 relatives were identified. For parents of patients with Crohn's disease, we observed 19 cases of colorectal cancer compared with 20 expected (standardized incidence ratio [SIR] = 1.0, 95 percent confidence interval [CI] = 0.6-1.5). For parents of patients with ulcerative colitis, 55 cases were observed compared with 51 expected (SIR = 1.1, CI = 0.8-1.4). CONCLUSIONS: The study did not corroborate the hypothesis that the same genetic factors play a significant role in the etiology of colorectal cancer and IBD, but more information is needed to disregard the possible link between IBD and colon cancer.

Adult↗
PubMed1998

Pregnancy experience in women who later developed oestrogen-related cancers (Denmark).

OBJECTIVES: There has been speculation that women with oestrogen-related cancers have been exposed to high levels of oestrogen in earlier life and therefore also during their pregnancies prior to the disease. For this reason we examined signs of reproductive outcome related to oestrogen exposure such as twinning, sex ratio, birth weight and congenital malformation in women who later were diagnosed with breast cancer, endometrial or ovarian cancer. METHODS: For 5213 children born to women who later developed breast cancer, 557 children born to women who later developed ovarian cancer and 173 children born to mothers with endometrial cancers we selected as a control four times as many newborns of mothers without these cancers after matching for mothers' parity, age, date of birth and hospital attended. All data were extracted from existing nationwide files. Most of the women's reproductive lives fell within the period of the birth registry from 1973 to 1993. RESULTS: No differences in sex ratio, birth weight or malformation were found between the newborns to cancer or control mothers in any of the cancer groups studied. The only significant findings were less than expected births of twins to mothers who later developed cancer of the ovaries and a higher proportion of newborns with a birth weight over 4000 g in the cancer corpus uterus group. CONCLUSION: Although the amount of information is limited for endometrial and ovarian cancers, we found no strong indication of elevated oestrogen levels during pregnancy.

Adult↗
PubMed1998

Lung cancer mortality among European rock/slag wool workers: exposure-response analysis.

OBJECTIVES: The purpose was to analyze the relationship between semi-quantitative indices of exposure to manmade vitreous fibers and lung cancer mortality among European rock/slag wool (RSW) workers. METHODS: The study population comprised 9,603 male workers employed in RSW production in seven factories in Denmark, Norway, Sweden, and Germany, followed up for mortality as of 1990-91. Estimates of past exposure to respirable fibers were used to calculate cumulative exposure with a 15-year lag and maximum annual exposure based on employment history up to 1977. Rate ratios were estimated via multivariate Poisson regression, adjusting for country, age, calendar year, time since first employment, and employment status. RESULTS: A total of 159 lung cancer deaths were included in the analysis of which 97 among workers with more than one year of employment. We found nonstatistically significant trends in lung cancer risk according to cumulative exposure. Relative risks (RR) in the four quartiles were 1.0 (reference), 1.3 (95 percent confidence interval [CI] = 0.8-2.4), 1.2 (CI = 0.7-2.1), and 1.5 (CI = 0.7-3.0, P test for trend = 0.4). When workers with less than one year of employment were excluded, there was no increased risk; the RRs in the four quartiles were 1.0, 0.9 (CI = 0.4-2.0), 0.8 (CI = 0.3-1.9), and 1.0 (CI = 0.4-2.7). No trend was present according to maximum annual exposure. The results were not consistent among countries. CONCLUSIONS: We found a positive association between exposure to respirable fibers and lung cancer mortality. However, the lack of statistical significance, the dependence of the results on inclusion of short-term workers, the lack of consistency among countries, and the possible correlation between exposure to respirable fibers and to other agents reduce the weight of such evidence.

Adult↗
PubMed1998

Diet during pregnancy and the risk of cerebral palsy.

The role of maternal diet in the development of the fetal brain has not been adequately explored. Marine n-3 fatty acids have, however, been proposed to be important for brain development. The present case-control study aimed to investigate the relationship between dietary intake during pregnancy and the occurrence of cerebral palsy (CP) in the offspring. Children with CP (n 109), born between 1984 and 1988 to mothers residing in the Greater Athens area, were identified at any time in 1991 or 1992 through institutions delivering care and rehabilitation. Successful nutritional interviews were conducted with ninety-one of these children. Controls were chosen among the neighbours of the CP cases or were healthy siblings of children with neurological diseases other than CP, seen by the same neurologists as the children with CP. A total of 278 control children were chosen, and 246 of them were included in the nutritional study. Guardians of all children were interviewed in person on the basis of a questionnaire covering obstetric, perinatal socioeconomic and environmental variables. A validated semiquantitative food-frequency questionnaire of 111 food items was used to estimate maternal dietary intake during pregnancy. Statistical analysis was done by modelling the data through logistic regression. Food groups controlling for energy intake were alternatively and simultaneously introduced in a core model containing non-nutritional confounding variables. Consumption of cereals (mostly bread) and fish intake were inversely associated with CP (P < 0.05 and P < 0.09 respectively) whereas consumption of meat was associated with increased risk (P < 0.02). A protective effect of fish consumption and a detrimental effect of meat intake have been suggested on the basis of earlier work and appear to be biologically plausible. If corroborated by other studies, these results could contribute to our understanding of the nutritional influences on fetal brain development.

Adult↗
PubMed1998

Fecundity in Thai and European regions: results based on waiting time to pregnancy.

Very little is known about the frequency of subfecundity in different cultures, ethnic groups and regions. To fill this gap, the European Study Group on Infertility and Subfecundity established data on the prevalence of infertility and subfecundity in five European regions. In this study, a comparison of fecundity was made between 4035 Caucasian women from five European countries and 1496 Asian women from southern Thailand. Fecundity was measured using 'time to pregnancy', i.e. the time women took to conceive after stopping contraceptive methods. The Thai primigravid women had a shorter time to pregnancy than European women, whereas time to pregnancy was found to be longer among Thai multigravidae, although this was not statistically significant. This study has illustrated that cross-culture comparison of subfecundity is difficult despite using a common protocol and questionnaire because of differences in the use of contraceptive methods and a different concept of pregnancy planning. The distribution of time to pregnancy for the Thai women was not outside the variation found within the European samples.

Adult↗
PubMed1998

Risk of preterm delivery, low birthweight and growth retardation following spontaneous abortion: a registry-based study in Denmark.

BACKGROUND: Some studies have found an association between spontaneous abortion and adverse birth outcome in the subsequent pregnancy, but results are conflicting, maybe due to lack of confounder control. METHODS: Using population-based registries we identified a cohort of 45 449 women having a livebirth preceded by a spontaneous abortion ('abortion cohort'), and a random sample of 9752 women with two consecutive livebirths ('reference cohort'). We examined the risk of preterm (<37 weeks gestation) and very preterm delivery (<34 weeks), low birthweight and growth retardation in both births in the reference cohort compared with births following an abortion, controlling for social factors and interpregnancy interval. RESULTS: Compared to second births in the reference cohort, the abortion cohort had higher risks for preterm (odds ratio [OR] = 1.74, 95% CI: 1.5-2.0) and very preterm delivery (OR = 2.17, 95% CI : 1.7-2.7), low birthweight (OR = 1.76, 95% CI: 1.5-2.1), and growth retardation (OR = 1.50, 95% CI: 1.4-1.6). In the reference cohort 3.9% of the pregnancies ended as preterm deliveries, 1 % as very preterm, 3.3% as low birthweight, and 8.1% as growth retarded. Women with two or more previous abortions had a higher risk for preterm and very preterm delivery. When first liveborns of women in the reference cohort were compared with first liveborns in the abortion cohort, only deliveries before 34 and 37 weeks' gestation were associated with previous abortion. CONCLUSIONS: Spontaneous abortion is associated with preterm delivery (both <34 and <37 weeks) in the subsequent pregnancy. Women who become pregnant following an abortion should receive special attention in the antenatal clinics.

Abortion, Spontaneous↗
PubMed1998

Alcohol and fetal damage.

Since the identification of fetal alcohol syndrome in the end of the 1960s, substantial evidence has accumulated on a number of adverse effects that alcohol consumption during pregnancy may have on the fetus. Long-term effects on child development has also been observed. Although the various types of effects are well documented, less is known about threshold levels of consumption, under which there is no risk of damage. Few studies have assessed the risk associated with high episodic drinking. From a theoretical point of view, binge drinking in critical stages in organ formation may constitute a particularly high risk for adverse outcomes.

Alcohol Drinking↗
PubMed1998

Mortality of short-term workers in two international cohorts.

The purpose of this study was to compare the pattern of mortality of blue-collar workers employed less and more than 1 year in the man-made vitreous fiber (MMVF) and the reinforced plastic industries, the latter group being exposed to styrene. We conducted an analysis among 21,784 workers with less than 1 year of employment (short-term workers) and 19,117 workers with 1 or more years of employment (long-term workers) employed in eight European countries. We conducted analyses based on external as well as internal comparisons. In both cohorts, the standardized mortality ratio for all causes among short-term workers was approximately 40% higher, compared with that for longer-term workers. In internal comparisons, the difference was reduced to 9% in the MMVF cohort and 11% in the styrene cohort. Workers with less than 1 month of employment displayed an increased mortality in both cohorts and in most countries. The increased mortality among short-term workers was not concentrated shortly after they quit employment. In both cohorts, short-term workers had a higher mortality from external causes, while little difference was seen in mortality from ischemic heart disease and malignant neoplasms. Although extra-occupational factors may contribute to increase the mortality of short-term workers and, in particular, of those employed for less than 1 month, the difference observed in analyses adjusted for characteristics of employment suggested a relatively small difference in mortality from most causes.

Adult↗
PubMed1998

Risk of breast cancer in men with liver cirrhosis.

OBJECTIVE: Liver cirrhosis is associated with increased levels of estrogens, which may be causally related to breast cancer. Because background estrogen levels are lower in men than in women, an estrogen-mediated link between liver cirrhosis and breast cancer would be easier to detect in men. METHODS: Men hospitalized with liver cirrhosis in Denmark from January 1, 1977, to December 31, 1989, were followed up, through record linkage, until the end of December 1993 for the possible occurrence of breast cancer. RESULTS: A total of 11,642 men with liver cirrhosis were identified and were followed for a mean period of 4.3 yr, for a total of 49,687 person-years. Three cases of male breast cancer were observed whereas 0.75 was expected, for a standardized incidence ratio of 4.0 (95% confidence interval, 0.8-11.7). CONCLUSIONS: Cirrhosis, possibly via high levels of endogenous estrogens, increases the risk of breast cancer in men.

Breast Neoplasms, Male↗
PubMed1998

Pregnancy outcome for women with Crohn's disease: a follow-up study based on linkage between national registries.

OBJECTIVE: Crohn's disease, characterized by chronic intestinal inflammation, is sometimes followed by malabsorption, which may interfere with embryogenesis and fetal growth. Therefore we examined birthweight, the frequency of preterm birth, and other reproductive outcomes in the offspring of women with Crohn's disease. METHODS: We used a historical registry-based study, with linkage between the Danish National Registry of Patients and the Danish Medical Birth Registry. Included were 510 newborns to mothers with Crohn's disease and 3018 controls in the study period from 1982 to 1992. RESULTS: The average birthweight of newborns to mothers with Crohn's disease was 185 g, 134 g less than expected for primiparas and multiparas. After adjusting for potential confounders the differences were 142 g (95% confidence interval [CI95%] = 76, 208) and 105 g (CI95% = 37, 173), respectively. The risk of low birthweight was increased in Crohn patients (odds ratio [OR] = 2.4; CI95% = 1.6-3.7), as was the risk of preterm birth (OR = 1.6; CI95% = 1.1-2.3). CONCLUSION: We found a lower birthweight in newborns of patients with Crohn's disease, indicating that Crohn's disease or its treatment may influence fetal growth.

Adult↗
PubMed1998

Are long working hours and shiftwork risk factors for subfecundity? A study among couples from southern Thailand.

OBJECTIVE: To estimate the effect of long working hours and shift work on time to pregnancy. METHODS: Cross sectional samples with retrospective data collection from two 700 bed hospitals at secondary to tertiary care level in Hatyai district, Songkhla Province, Thailand. The study was conducted from March 1995 to November 1995 among 1496 pregnant women attending the antenatal clinics. Subfecundity was defined as time to pregnancy longer than 7.8, 9.5, or 12 months (time to pregnancy was calculated from the date at which the couples started having sexual relations without any contraception until last menstrual date). RESULTS: The descriptive analyses were restricted to 1201 planned pregnancies and the analytical part to 907 working women. Separate analyses on primigravid women were also done. Logistic regressions adjusted for age, education, body mass index, menstrual regularity, obstetric and medical history, coital frequency, and potential exposure to reproductive toxic agents, showed an odds ratio (OR) associated with female exposure to long working hours of 2.3 (95% confidence interval (95% CI) 1.0 to 5.1) in primigravid and 1.6 (1.0 to 2.7) in all pregnant women. Male exposure to long working hours and shiftwork showed no association with subfecundity. The OR of subfecundity was highest when both partners worked > 70 hours a week irrespective of the cut off point used (OR 4.1 (95% CI 1.3 to 13.4) in primigravid women; OR 2.0 (95% CI 1.1 to 3.8) in all pregnant women). CONCLUSIONS: Long working hours is a risk factor for subfecundity especially for women. Shiftwork was not associated with subfecundity in this study.

Adolescent↗
PubMed1998

Job strain and time to pregnancy.

OBJECTIVES: The association between fertility and job strain defined as high job demands and low job control has not previously been studied. A follow-up study was conducted with prospective collection of information on job strain among women, achievement of pregnancy, and potential confounding variables. METHODS: A total of 297 Danish couples without previous reproductive experience was followed for a maximum of 6 menstrual cycles from termination of birth control until pregnancy. Job demand and job control were measured by a questionnaire developed by Karasek and his co-workers. RESULTS: The odds ratio and 95% confidence interval (95% CI) for conception per menstrual cycle for women with high job strain was 0.9 (95% CI 0.5-1.5) when compared with that of women in low-strain jobs. Only in secondary analyses restricted to couples with no suspected competitive causes of reduced fertility was a statistically significant reduced odds found for women with high-strain jobs compared with all other jobs. CONCLUSIONS: The main finding of this study did not corroborate a hypothesis of a substantial detrimental effect of job strain on fecundability.

Adult↗
PubMed1998

Year of birth and sperm count in 10 Danish occupational studies.

OBJECTIVES: Several reports indicate a secular decline of human sperm counts. It is still not known if these findings are artifacts related to shortcomings in the data and applied methodologies. Even less is known about possible mechanisms, but it has been proposed that potential changes may be related to disruption of the hormonal regulation of testicular development in prenatal life. The objective of this study was to examine whether sperm count was related to year of birth. METHODS: An analysis was made of the sperm count of 1196 men participating in 10 cross-sectional occupational sperm studies in 3 regions of Denmark from 1986 through 1995. RESULTS: The median sperm concentration was 63 million per milliliter for men born in 1937-1949 and 52 million per milliliter for men born in 1970 or later, and the median total sperm was 206 million and 117 million, respectively. The inverse relationship between sperm concentration and year of birth was statistically significant even after adjustment for duration of sexual abstinence, season of the year, and study population. However, bias because of differential participation related to age and fertility or lack of comparability across the populations cannot be ruled out. CONCLUSIONS: The apparent decline of sperm count with increasing year of birth is compatible with the hypothesis of a common risk factor for male reproductive health operating in prenatal life or early childhood, but the evidence is circumstantial. Age-related selection bias is an alternative and perhaps not a less likely explanation.

Adult↗
PubMed1998

Third generation oral contraceptives and heritable thrombophilia as risk factors of non-fatal venous thromboembolism.

Third generation oral contraceptives (OCs) are apparently stronger risk factors for venous thromboembolism (VTE) than other OCs, however, the increased risk may be due to confounding by indication related to differences in prescription behaviour. We estimated the risk of VTE associated with use of OCs with and without the presence of Factor V Leiden mutation, protein C-, protein S- or antithrombin deficiency. Sixty-seven cases with VTE were compared with 134 controls. The risk of VTE in the presence of thrombophilia was of the same magnitude for third generation OC users as for users of other OCs; OR: 52.5 (95% CI: 3.7-738.1) and OR: 63.3 (95% CI: 6.2-648.4), respectively. It is unlikely that confounding by indication entirely explains the risk of VTE associated with third generation OCs since the combined effect exceeds what could be explained if this source of error was the only determinant of the association.

Adult↗